Dr. Becky L. Genberg, assistant professor of health services, policy and practice in the Brown University School of Public Health, and colleagues in a June article in the Lancet HIV comment on Roger Ying and colleagues’ home testing and counselling to reduce HIV incidence in a generalised epidemic setting: A mathematical modelling analysis. Ying concludes from a mathematical modelling study that home testing and counselling (HTC) every five years could lead to reductions in HIV incidence, even without universal treatment.
[Photo: Dr. Becky L. Genberg]
Genberg and colleagues agree that, though logistically intensive, HTC is feasible, acceptable, and effective at achieving high coverage at the population level. No other testing approach could diagnose HIV-positive people more comprehensively. However, they point out that linkage to care rates might be low if not actively facilitated.
The comment describes Ying and colleagues’ comprehensive and carefully constructed model and their use of state-of-the-art computing methods to generate projections of HIV prevalence and incidence under different policies. According to Genberg, the degree of model complexity is high relative to the amount of data used to inform the fitting process. They recommend that simpler or more parsimonious models, to the extent that they can be calibrated to observed data and reflect relevant sources of uncertainty, might serve to make inferences about comparative effectiveness more transparent and convincing to end-users and policy makers.
They suggest that it might be time to emphasize efficacy over cost-effectiveness, especially when cost-effectiveness can lead to the recommendation of strategies with suboptimal efficacy, such as delayed treatment. Available evidence suggests the need for innovative methods to newly diagnosed people with HIV and to promote their engagement in care.
In many settings, Genberg says, the infrastructure for treatment delivery exists, but strategies to identify and engage all those who need it do not. Until they do, there is a risk of failing to capitalize fully on previous accomplishments and the potential of modern ART to halt HIV.
The comment was published June 2016 in Lancet HIV Volume 3, No. 6.